CN111307956B - Guided wave signal excitation circuit based on linear frequency modulation signal - Google Patents
Guided wave signal excitation circuit based on linear frequency modulation signal Download PDFInfo
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Abstract
The invention discloses a guided wave signal excitation circuit based on a linear frequency modulation signal, namely a programmable, high-power, high-amplitude and easy-to-use guided wave excitation circuit capable of exciting a wideband linear Chirp signal, which comprises a Chirp signal waveform synthesis circuit, a passive low-pass filter circuit, a gain amplification circuit, a power amplification circuit, a switch direct current boost circuit (boost circuit) and an FPGA control circuit. The Chirp signal waveform synthesis circuit may output an original linear Chirp signal. The original linear Chirp signal is taken as input to enter a passive low-pass filter circuit, so that spurious phenomena brought by a Chirp signal waveform synthesis circuit are eliminated, and the denoised linear Chirp signal is output. The linear Chirp signal after denoising is amplified in two stages through the gain amplifying circuit and the power amplifying circuit, and then the low voltage can be further stably increased to 300V high voltage through the boost circuit, and finally the linear Chirp signal after boosting is output. The circuit provides an effective technical means for realizing sweep frequency test and multi-mode and multi-frequency band detection by ultrasonic guided waves.
Description
Technical Field
An ultrasonic guided wave excitation circuit capable of generating linear frequency modulation signals for exciting a piezoelectric transducer is realized, and belongs to the field of nondestructive detection
Background
The ultrasonic guided wave detection technology is a nondestructive detection method capable of being used for long distance, high speed and large range, and can detect the conditions of the surface and the inside of a test piece by adopting a line scanning mode, and even detect the defects of special parts which cannot be achieved by a conventional detection mode. Meanwhile, the technology has the advantages of short time, high efficiency, high flexibility, strong applicability, no harm to human bodies and environment, and the like, and can be spread in liquid and solid, and the technology is already applied to a plurality of detection fields such as pipelines, roads and bridges, bonding quality, composite materials and the like. The core of this technique is to excite ultrasonic guided waves that are suitable for propagation in the test object. The common ultrasonic guided wave excitation signal modulates a sine signal for a narrow-band window function so as to inhibit the dispersion to the maximum extent, but limits the frequency range of the excitation signal and reduces the universality of the ultrasonic guided wave to complex components. In the past, two kinds of waveguide detection devices are widely used internationally, namely a WaveMarker of the GUL company in the United kingdom and an MsSR3030 waveguide detection system developed by the southwest research institute in the United states, and the two kinds of devices are used for realizing defect detection by exciting a single mode at a frequency point with small dispersion. Because the excitation circuits in the devices can only generate a certain fixed type of narrow-band pulse, the excitation circuits do not have the function of exciting the piezoelectric transducer to generate a wide-frequency waveform, and the further development of the guided wave detection technology is greatly limited. The frequency band of the linear Chirp signal is wide, the echo signal which is equal to the echo signal received when the sine wave signal modulated by the window function is excited can be obtained by post-processing the received echo signal, the frequency of the modulated sine wave can be any frequency in the frequency band range of the linear Chirp signal, and an effective technical means is provided for ultrasonic guided wave sweep frequency test and multi-mode and multi-band detection.
Disclosure of Invention
The invention aims to provide a guided wave signal excitation circuit based on a linear frequency modulation signal, namely a programmable, high-power, high-amplitude and easy-to-use guided wave excitation circuit capable of exciting a wideband linear Chirp signal.
The guided wave signal excitation circuit design based on the linear frequency modulation signal comprises a Chirp signal waveform synthesis circuit, a passive low-pass filter circuit, a gain amplification circuit, a power amplification circuit, a switching direct current boost circuit (boost circuit) and an FPGA control circuit. The Chirp signal waveform synthesis circuit can realize multiple functions of mode selection, frequency modulation, phase modulation, amplitude modulation and the like of an excitation signal, and output an original linear Chirp signal. However, the Chirp signal waveform synthesis circuit introduces errors due to phase truncation, so that a large part of noise signals are mixed in the original linear Chirp signal. The passive low-pass filter circuit can realize the function of an elliptic low-pass filter, the passband and the stopband of the elliptic low-pass filter are jittering, but the transition band is narrower than the passband and drops rapidly, so that the excitation signal stray phenomenon brought by the Chirp signal waveform synthesis circuit can be eliminated, the original linear Chirp signal enters the passive low-pass filter circuit as input, and the output is subjected to denoising. Meanwhile, in order to meet the requirement of large-range long-distance detection, the signal with larger energy needs to be obtained, so that the denoised linear Chirp signal needs to be amplified in two stages through a gain amplifying circuit and a power amplifier, and the amplified linear Chirp signal is output. The boost circuit can further stably boost the low-voltage amplified linear Chirp signal to 300V high voltage, the boosted linear Chirp signal is output, and the voltage can be realized by using an FPGA control circuit to regulate PWM signals.
The FPGA control circuit controls the whole process of waveform data transmission, storage, waveform synthesis and program control amplification.
The Chirp signal waveform synthesis circuit is characterized in that: the core chip in the Chirp signal waveform synthesis circuit is provided with a high-speed and high-performance orthogonal digital-analog converter, so that an original linear Chirp signal can be generated, and the voltage amplitude of the output original linear Chirp signal is in a lower range.
The passive low-pass filter circuit is characterized in that: the passive low-pass filter circuit realizes the function of a 7-order elliptic low-pass filter, the low-pass bandwidth of the filter is more than or equal to 10MHz, the cut-off frequency is high, the attenuation is large, the signal spurious phenomenon which can be introduced by the phase truncation phenomenon of the Chirp signal waveform synthesis circuit can be effectively removed, and the linear Chirp signal after noise removal is output.
The gain amplifying circuit is characterized in that: gain amplification of 0-30 dB of the signal can be realized, the voltage of the linear Chirp signal after denoising is amplified, and the linear Chirp signal after amplifying the voltage is output.
The power amplifying circuit is characterized in that: when power is supplied, the output voltage can reach plus or minus 225V, the power supply voltage is provided by a boost circuit, the output current can reach higher, the high power supply voltage suppression ratio is realized, the effective suppression capability of the circuit on power supply noise can be ensured, the linear Chirp signal is used as an in-out signal after the voltage is amplified, and finally the amplified linear Chirp signal is output.
The power amplifying circuit is characterized in that: r95 and C112 are connected in series and then connected into a power amplifying circuit to form an external RC network of the power amplifying circuit so as to increase the stability of the operational amplifier and expand the frequency band, and the closed-loop bandwidth can reach at least 1MHz. One end of the R94 is grounded, and the other end of the R94 is connected with the amplified linear Chirp signal output end to become a load resistor, so that the capacity of driving a load is improved.
The boost circuit is characterized in that: the amplified linear Chirp signal is used as a circuit input signal and is output as a boosted linear Chirp signal, the voltage of the boosted linear Chirp signal is mainly determined by the duty ratio of a PWM signal output by an FPGA control circuit, and a boost circuit mainly comprises a digital signal isolation circuit, a feedback loop, a hardware PI circuit, a switching power supply circuit and a boost circuit.
The digital signal isolation circuit is characterized in that: an optocoupler 6N137S is used to isolate the transmission of the signal. The PWM signal is a signal output by the FPGA, the output of the optocoupler is inverted by the triode Q7 and then is output to the shaping circuit comparator TLC2272CD, the output signal of the optocoupler is subjected to passive low-pass filtering to output stable direct-current voltage control U1, and the size of the U1 and the PWM duty ratio are in linear relation.
The feedback loop is characterized in that: after the HIGH-VOLTAGE input HIGH-VOLTAGE is divided by R74 and R79, the HIGH-VOLTAGE input HIGH-VOLTAGE is input into an operational amplifier which can isolate input and output and is used as a VOLTAGE follower, and the influence of a later-stage circuit on the R74 and R79 VOLTAGE division is eliminated.
The hardware PI circuit is characterized in that: the output voltage difference between the control voltage U1 and the feedback loop determines the output size of the control voltage U2 by adopting the principle of a proportional integral circuit TLC2272 CD.
The FPGA control circuit and the switching power supply circuit are characterized in that: the frequency of PWM signals output by the FPGA control circuit is determined by C104 and R90, the frequency of PWM output can be adjusted by adjusting R25, when the internal transistor of TL494 is turned on, the power supply 12V is added to the base electrode of the triode Q9 through C1, E1 and R90, the triode Q9 is turned on, the Q8 is turned off, the U18 power tube is turned on, and the PWM signal output is high. When the internal transistor is turned off, the base current is zero, so that the triode Q9 is turned off, the triode Q8 is turned on, the grid capacitor of the power tube discharges through the collecting junction channel of the triode Q8, and the PWM signal output is low.
The switching power supply circuit is characterized in that: the inductor L11, the inductor C99 and the inductor C100 form a filter circuit, and the inductor R75 is a load. When the PWM signal is low, the diode D23 is reversely biased and cut off, the 12V VOLTAGE is L10 to be charged, when the PWM signal is HIGH, the diode D23 is positively biased and conducted, the 12V VOLTAGE and the induced electromotive force of the L10 are charged to C7 through the D23, and HIGH-VOLTAGE output is achieved.
The boost circuit is characterized in that: the inductor L11, the inductor C99 and the inductor C100 form a filter circuit, and the inductor R75 is a load. When the PWM signal is low, the diode D23 is reversely biased and cut off, the 12V VOLTAGE is L10 to be charged, when the PWM signal is HIGH, the diode D23 is positively biased and conducted, the 12V VOLTAGE and the induced electromotive force of the L10 are charged to C7 through the D23, and HIGH-VOLTAGE output is achieved.
Drawings
FIG. 1 is a schematic block diagram of a guided wave signal excitation circuit based on a chirp signal;
FIG. 2 Chirp signal waveform synthesis circuit design diagram
FIG. 3 is a passive low pass filter circuit;
FIG. 4 is a gain amplification circuit design;
FIG. 5 is a power amplifier circuit layout;
FIG. 6 is a diagram of a digital signal isolation circuit;
FIG. 7 is a feedback loop and hardware PI circuit design;
FIG. 8 is a circuit diagram of a switching power supply;
FIG. 9 boost circuit design is as shown;
FIG. 10 Chirp signal test results plot;
FIG. 11 is a diagram of a Chirp signal spectrum analysis;
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings:
the guided wave signal excitation circuit design based on the linear frequency modulation signal comprises a Chirp signal waveform synthesis circuit, a passive low-pass filter circuit, a gain amplification circuit, a power amplification circuit and a switch direct current booster circuit
The functional block diagram of the guided wave signal excitation circuit based on the chirp signal is shown in fig. 1.
The FPGA in this embodiment is a Kintex-7XC7K70T chip from Xilinx corporation. The FPGA controls the whole process of transmission, storage, waveform synthesis and program-controlled amplification of waveform data. The core chip of the Chirp signal waveform synthesis circuit adopts AD9854, and the working Mode is set to be a Chirp (Mode 011) Mode, and the design diagram of the Chirp signal waveform synthesis circuit is shown in fig. 2. The Chirp signal waveform synthesis circuit is provided with two 12-bit high-speed high-performance orthogonal digital-analog converters, signals can be converted into original linear Chirp signals, the voltage amplitude of the signals output at the moment is about 0.3-0.5V, signal errors can be introduced due to the phase truncation phenomenon of the circuit, and then the original linear Chirp signals enter a passive low-pass filter circuit.
The passive low pass filter circuit in this example implements a 7-order elliptical low pass filter function, as shown in fig. 3. The low-pass bandwidth of the filter is 10MHz, the attenuation is 70.3dB when the cut-off frequency is 12.1MHz, the spurious phenomenon of an excitation signal brought by a Chirp signal waveform synthesis circuit can be effectively removed, an original linear Chirp signal is output as a denoised linear Chirp signal, and then the denoised linear Chirp signal enters a gain amplification circuit.
In the embodiment, the core chip of the gain amplifying circuit is MAX437, the circuit design is shown in fig. 4, the circuit can realize the gain of 0-30 dB of the excitation signal, and the linear Chirp signal after denoising with the original voltage amplitude of 0.3-0.5V is amplified into the voltage signal of 0-10V. In the guided wave detection process, the higher the excitation frequency is, the higher the detection precision is, and the faster the energy attenuation of the guided wave is, so that the voltage signal amplified to 0-10V enters a power amplifying circuit for ensuring that the signal has enough energy.
The core chip adopted by the power amplifying circuit in the example is PA98, the design of the power amplifying circuit is shown in fig. 5, and the output signal is an amplified linear Chirp signal. When the PA98 is powered on at two ends, the output voltage can reach plus or minus 225V, the power supply voltage is provided by a boost circuit, the output current can reach 200mA, the slew rate under the condition of adding an external compensation capacitor is 400V/mu s, the maximum input offset voltage is 0.5mV, and the power supply voltage suppression ratio is very high, so that the circuit can be ensured to have effective suppression capability on power supply noise. R95 and C112 in the circuit form an external RC network of the PA85, so that the stability and the expansion frequency band of the operational amplifier can be increased, the values of the phase compensation capacitor R95 and the resistor C112 are respectively 3.3pF and 100R, and the closed-loop bandwidth can reach 1MHz. One end of the R94 is grounded, the other end of the R94 is connected with the amplified linear Chirp signal output end, the R93 is a current limiting resistor, the R94 is a load resistor, in order to improve the capacity of driving a load, the resistance value of the load resistor R94 is configured to be 2K, and the current is limited within 165mA by matching with the R93 current limiting resistor with the resistance value of 5.1 omega.
The voltage level of the boosted linear Chirp signal output by the boost circuit in the example is mainly determined by the duty ratio of PWM output by the FPGA control circuit, and the circuit is mainly composed of a digital signal isolation circuit, a feedback loop, a hardware PI circuit, a switching power supply circuit and a boost circuit.
The digital signal isolation circuit design in this example is shown in fig. 6. In order to prevent interference of the latter-stage circuit to the FPGA circuit, an optocoupler 6N137S is used to isolate transmission of signals. The PWM signal is a signal output by the FPGA, the output of the optocoupler is inverted by the triode Q7 and then is output to the shaping circuit comparator TLC2272CD, the output signal of the optocoupler is subjected to passive low-pass filtering to output stable direct-current voltage control U1, and the size of the U1 and the PWM duty ratio are in linear relation.
The design diagram of the feedback loop and the hardware PI circuit in this example is shown in fig. 7, where the resistance ratio of the feedback loop HIGH-VOLTAGE input HIGH-VOLTAGE is 100: after the R74 and R79 of the 1 are divided, the voltage is input into an operational amplifier which can isolate the input from the output and is used as a voltage follower, so that the influence of a later-stage circuit on the R74 and R79 divided voltage can be eliminated. The hardware PI circuit mainly utilizes the principle of a proportional integral circuit TLC2272CD, and the output voltage difference value of the control U1 and the feedback loop determines the output size of the control voltage U2.
The core of the switching power supply circuit in this example is TL494, and the circuit design is shown in fig. 8. The frequency of the output PWM signal is determined by C104 and R90, the frequency of the output PWM can be adjusted by adjusting R25, when the transistor in TL494 is turned on, the power supply 12V is added to the base electrode of the triode Q9 through C1, E1 and R90, the triode Q9 is turned on, the triode Q8 is turned off, the U18 power tube is turned on, and the PWM signal output is high. When the internal transistor is turned off, the base current is zero, so that the triode Q9 is turned off, the triode Q8 is turned on, the grid capacitor of the power tube discharges through the collecting junction channel of the triode Q8, and the PWM signal output is low.
The boost circuit design in this example is shown in fig. 9. The inductor L11, the inductor C99 and the inductor C100 form a filter circuit, and the inductor R75 is a load. When the PWM signal is low, the diode D23 is reversely biased and cut off, the 12V VOLTAGE is L10 to be charged, when the PWM signal is HIGH, the diode D23 is positively biased and conducted, the 12V VOLTAGE and the induced electromotive force of the L10 are charged to C7 through the D23, and HIGH-VOLTAGE output is achieved.
The test was performed using the chirp signal-based guided wave signal excitation circuit in this example, by first downloading the FPGA logic control program to the FPGA development board, setting the excitation start frequency to 450kHz, the frequency resolution to 10kHz, and the termination frequency to 650kHz, the test results are shown in fig. 10. See fig. 11 by spectral analysis of the excited Chirp signal. It can be seen that the jitter is relatively large in the frequency band range of the signal, but the frequency band range and the set frequency band parameters are substantially identical.
Finally, it should be noted that the above-mentioned embodiments illustrate rather than limit the technical solution described in the present invention, and therefore, although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the present invention may be modified or equivalently replaced without departing from the spirit and scope of the invention, and all such modifications are intended to be included in the scope of the claims of the present invention.
Claims (13)
1. The utility model provides a but, high-power, high-amplitude, easy-to-use guided wave excitation circuit of broadband linear Chirp signal can be excited to guided wave signal excitation circuit based on Chirp signal, includes Chirp signal waveform synthesis circuit, passive low pass filter circuit, gain amplifier circuit, power amplifier circuit and switch direct current boost circuit, FPGA control circuit, its characterized in that:
a) The Chirp signal waveform synthesis circuit can realize the functions of mode selection, frequency modulation, phase modulation and amplitude modulation of the excitation signal, output the original linear Chirp signal,
b) The passive low-pass filter circuit can realize the function of an elliptic low-pass filter, the passband and the stopband of the elliptic low-pass filter are jittering, but the transition band is narrower than the passband and drops rapidly, so that the signal spurious phenomenon brought by the Chirp signal waveform synthesis circuit can be eliminated, the original linear Chirp signal enters the passive low-pass filter circuit as input, the output denoised linear Chirp signal,
c) The denoised linear Chirp signal is used as input and sequentially enters a gain amplifying circuit and a power amplifying circuit,
realizes the two-stage amplification process of the denoised linear Chirp signal, outputs the amplified linear Chirp signal with larger energy, realizes the large-range long-distance detection,
the amplified linear Chirp signal is used as input to enter a switch direct current booster circuit, the low voltage is stably boosted to 300V high voltage, the boosted linear Chirp signal is output, and the voltage can be controlled by an FPGA (field programmable gate array) by utilizing the adjustment of PWM (pulse Width modulation) signals output by the FPGA control circuit.
2. The guided wave signal excitation circuit of claim 1, wherein: a core chip in the Chirp signal waveform synthesis circuit is provided with a high-speed and high-performance orthogonal digital-analog converter, so that an original linear Chirp signal is generated, and the voltage amplitude of the output original linear Chirp signal is reduced.
3. The guided wave signal excitation circuit of claim 1, wherein: the passive low-pass filter circuit realizes the function of a 7-order elliptic low-pass filter, the low-pass bandwidth of the filter is more than or equal to 10MHz, the cut-off frequency is high, the attenuation is large, the signal spurious phenomenon introduced by the Chirp signal waveform synthesis circuit due to phase truncation is removed, and the linear Chirp signal after noise removal is output.
4. The guided wave signal excitation circuit of claim 1, wherein: the gain amplifying circuit realizes gain amplification of 0-30 dB of the signal, amplifies the voltage of the linear Chirp signal after denoising, and outputs the amplified voltage of the linear Chirp signal.
5. The guided wave signal excitation circuit of claim 1, wherein: when the power amplifying circuit supplies power, the amplitude of the output voltage is positive and negative 225V, the power supply voltage is provided by the switch direct current booster circuit, the output current has high power supply voltage suppression ratio and is used for guaranteeing that the circuit has effective suppression capability on power supply noise, the amplified voltage is taken as an input and output linear Chirp signal, and finally the amplified linear Chirp signal is output.
6. The guided wave signal excitation circuit of claim 1 or 5, wherein: the power amplifying circuit R95 and the power amplifying circuit C112 are connected in series and then connected into the power amplifying circuit to form an external RC network of the power amplifying circuit, and the external RC network is used for increasing the stability of the operational amplifier and expanding the frequency band, and the bandwidth of the closed loop is larger than 1MHz; one end of the R94 is grounded, and the other end of the R94 is connected with the amplified linear Chirp signal output end to become a load resistor, so that the capacity of driving a load is improved.
7. The guided wave signal excitation circuit of claim 1, wherein: the switching direct current boost circuit is also called a boost circuit, the linear Chirp signal after the amplification of the switching direct current boost circuit is used as a circuit input signal and is output as a boosted linear Chirp signal, the voltage of the boosted linear Chirp signal is determined by the duty ratio of a PWM signal output by the FPGA control circuit, and the boost circuit consists of a digital signal isolation circuit, a feedback loop, a hardware PI circuit, a switching power supply circuit and a boost circuit.
8. The guided wave signal excitation circuit of claim 7, wherein: the digital signal isolation circuit adopts an optocoupler 6N137S to isolate signal transmission; the PWM signal is a signal output by the FPGA control circuit, the output of the optocoupler is inverted by the triode Q7 and then is output to the shaping circuit comparator TLC2272CD, the output signal of the optocoupler is subjected to passive low-pass filtering to output stable direct-current voltage control U1, and the size of the U1 and the duty ratio of the PWM signal are in a linear relation.
9. The guided wave signal excitation circuit of claim 7, wherein: after the HIGH-VOLTAGE input HIGH-VOLTAGE of the feedback loop is divided by R74 and R79, the HIGH-VOLTAGE input HIGH-VOLTAGE is input into an operational amplifier which can isolate input and output and is used as a VOLTAGE follower, and the influence of a later-stage circuit on the R74 and R79 VOLTAGE is eliminated.
10. The guided wave signal excitation circuit of claim 7, wherein: the hardware PI circuit adopts the principle of a proportional integral circuit TLC2272CD, and the output voltage difference value of the control U1 and the feedback loop determines the output size of the control voltage U2.
11. The guided wave signal excitation circuit of claim 7, wherein: the frequencies of PWM signals output by the FPGA control circuit in the FPGA control circuit and the switching power supply circuit are determined by C104 and R90, the frequency of PWM output can be adjusted by adjusting R25, when the transistor in TL494 is conducted, the power supply 12V is added to the base electrode of the triode Q9 through C1, E1 and R90, the triode Q9 is conducted, the Q8 is cut off, the U18 power tube is conducted, and the PWM signal output is high; when the internal transistor is turned off, the base current is zero, so that the triode Q9 is turned off, the triode Q8 is turned on, the grid capacitor of the power tube discharges through the collecting junction channel of the triode Q8, and the PWM signal output is low.
12. The guided wave signal excitation circuit of claim 7 or 10, wherein: the switching power supply circuit inductance L11, the C99 and the C100 form a filter circuit, and R75 is a load; when the PWM signal is low, diode D23 reverse biases off, 12V charges L10; when the PWM signal is high, the diode D23 is forward biased to be conducted, and the induced electromotive force of the voltage of 12V and the voltage of L10 charges C7 through the D23, so that high-voltage output is realized.
13. The guided wave signal excitation circuit of claim 7, wherein: the boost circuit comprises an inductor L11, a filter circuit formed by C99 and C100, and R75 is a load; when the PWM signal is low, the diode D23 is reversely biased and cut off, the 12V VOLTAGE is L10 to be charged, when the PWM signal is HIGH, the diode D23 is positively biased and conducted, the 12V VOLTAGE and the induced electromotive force of the L10 are charged to C7 through the D23, and HIGH-VOLTAGE output is achieved.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4224035A1 (en) * | 1992-07-21 | 1994-01-27 | Siemens Ag | Ultrasound test method for flaw location - using frequency modulated chirp signal whose instantaneous frequency time characteristic is matched to transfer function of transmission path |
| US5400350A (en) * | 1994-03-31 | 1995-03-21 | Imra America, Inc. | Method and apparatus for generating high energy ultrashort pulses |
| US7126100B1 (en) * | 2004-05-21 | 2006-10-24 | Kla-Tencor Technologies Corporation | System and method for sensing using adjustable modulation transfer function (MTF) |
| US7246522B1 (en) * | 2006-02-24 | 2007-07-24 | Battelle Memorial Institute | Methods and apparatus for multi-parameter acoustic signature inspection |
| CN101642405A (en) * | 2009-06-19 | 2010-02-10 | 中国科学院声学研究所 | Ultrasonic blind guide method and portable ultrasonic blind guide device thereof |
| CN104515809A (en) * | 2015-01-15 | 2015-04-15 | 重庆大学 | Device and method for identifying identities of power cables based on ultrasonic wave |
| CN104577689A (en) * | 2013-10-14 | 2015-04-29 | 韩国科学技术院 | Electronic dispersion compensation for low cost distributed feedback directly modulated lasers |
| CN105241949A (en) * | 2015-10-16 | 2016-01-13 | 中国航空工业集团公司北京长城航空测控技术研究所 | Detection circuit of grease metal filing online monitor and carrier signal demodulation method |
| CN105548373A (en) * | 2015-12-15 | 2016-05-04 | 华南理工大学 | Quasi one-time orthogonal complementary Golay (A,B) code ultrasonic phased array coded excitation method |
| CN107976484A (en) * | 2017-11-22 | 2018-05-01 | 武汉市工程科学技术研究院 | Linear frequency modulation anchor pole detects transceiver sensor and anchor pole detection method |
| CN208156449U (en) * | 2017-12-25 | 2018-11-27 | 中北大学 | IEPE sensor programmable conditioning circuit |
| CN208942190U (en) * | 2018-06-01 | 2019-06-07 | 辽东学院 | Miniaturized ultrasonic imaging device based on pulse compression |
| CN110098763A (en) * | 2019-05-10 | 2019-08-06 | 天津科技大学 | A kind of supersonic guide-wave drive power supply for piezoelectric ceramics based on FPGA |
| CN110572152A (en) * | 2018-06-06 | 2019-12-13 | 恩智浦美国有限公司 | Boosted return time and calibration method for fast chirped PLL |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5411417B2 (en) * | 2007-09-11 | 2014-02-12 | 古野電気株式会社 | Pulse signal transmission / reception device and transmission / reception method |
| GB201222882D0 (en) * | 2012-12-19 | 2013-01-30 | Univ Leeds | Ultrasound generation |
| US9172359B2 (en) * | 2014-03-04 | 2015-10-27 | Raytheon Company | Flexible chirp generator |
-
2019
- 2019-12-19 CN CN201911323066.3A patent/CN111307956B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4224035A1 (en) * | 1992-07-21 | 1994-01-27 | Siemens Ag | Ultrasound test method for flaw location - using frequency modulated chirp signal whose instantaneous frequency time characteristic is matched to transfer function of transmission path |
| US5400350A (en) * | 1994-03-31 | 1995-03-21 | Imra America, Inc. | Method and apparatus for generating high energy ultrashort pulses |
| US7126100B1 (en) * | 2004-05-21 | 2006-10-24 | Kla-Tencor Technologies Corporation | System and method for sensing using adjustable modulation transfer function (MTF) |
| US7246522B1 (en) * | 2006-02-24 | 2007-07-24 | Battelle Memorial Institute | Methods and apparatus for multi-parameter acoustic signature inspection |
| CN101642405A (en) * | 2009-06-19 | 2010-02-10 | 中国科学院声学研究所 | Ultrasonic blind guide method and portable ultrasonic blind guide device thereof |
| CN104577689A (en) * | 2013-10-14 | 2015-04-29 | 韩国科学技术院 | Electronic dispersion compensation for low cost distributed feedback directly modulated lasers |
| CN104515809A (en) * | 2015-01-15 | 2015-04-15 | 重庆大学 | Device and method for identifying identities of power cables based on ultrasonic wave |
| CN105241949A (en) * | 2015-10-16 | 2016-01-13 | 中国航空工业集团公司北京长城航空测控技术研究所 | Detection circuit of grease metal filing online monitor and carrier signal demodulation method |
| CN105548373A (en) * | 2015-12-15 | 2016-05-04 | 华南理工大学 | Quasi one-time orthogonal complementary Golay (A,B) code ultrasonic phased array coded excitation method |
| CN107976484A (en) * | 2017-11-22 | 2018-05-01 | 武汉市工程科学技术研究院 | Linear frequency modulation anchor pole detects transceiver sensor and anchor pole detection method |
| CN208156449U (en) * | 2017-12-25 | 2018-11-27 | 中北大学 | IEPE sensor programmable conditioning circuit |
| CN208942190U (en) * | 2018-06-01 | 2019-06-07 | 辽东学院 | Miniaturized ultrasonic imaging device based on pulse compression |
| CN110572152A (en) * | 2018-06-06 | 2019-12-13 | 恩智浦美国有限公司 | Boosted return time and calibration method for fast chirped PLL |
| CN110098763A (en) * | 2019-05-10 | 2019-08-06 | 天津科技大学 | A kind of supersonic guide-wave drive power supply for piezoelectric ceramics based on FPGA |
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